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Bearoff position, cubeful ROLLOUT - Gnubg

Posted By: Daniel Murphy
Date: Thursday, 19 September 2013, at 4:16 a.m.

In Response To: Bearoff position, cubeful ROLLOUT (ah_clem)

Money game. Blue to play 5-3.

White	87
Blue	39
Position ID: ttsNABDPvQEAAA Match ID: QYkOAAAAAAAA

My Gnubg rollout agrees that the best play is 5/off 4/1. This leaves 11 immediate shots but is quite safe thereafter. Only 3-3 leaves a shot next roll. But there is a chance of blotting after that, also.

The second best play is 5/off 5/2*. This play also leaves 11 immediate shots but perhaps surprisingly must be even safer because it wins the most games. White must leave with any 5 or 6 except 5-2 and 6-2 (16 numbers). If White does not leave, many of Blue's rolls do not cover or lift the 2 point blot, but they only matter when White has fanned (9 numbers). It's the DMP play.

Thus 5/off 4/1 is better because it wins more gammons. I believe it wins more gammons because (a) it doesn't force White to leave with many rolls (like any 5 or 6 except 6-2 and 6-2 after 5/off 5/2*) -- so White must stay (as he would like to stay) and gets gammoned a bit more often for it and (b) it gives Blue 8 pointing numbers, provided White hasn't run with 6-6.

The greedy 5/off 3/off simply leaves too many shot numbers next roll (66 55 44 and 33).

#		Ply	Move	Equity
•	1	R	5/off 4/1	+0.3378
			0.6946 0.0339 0.0002 - 0.3054 0.0000 0.0000 +0.4233 +0.3378 0.0004 0.0006 0.0000 - 0.0004 0.0000 0.0000 0.0007 0.0010
			Full cubeful rollout with var.redn.
			1297 games, Mersenne Twister dice gen. with seed 722859899 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	2	R	5/2* 5/off	+0.3267 ( -0.0111)
			0.6973 0.0244 0.0001 - 0.3027 0.0000 0.0000 +0.4193 +0.3267 0.0003 0.0004 0.0000 - 0.0003 0.0000 0.0000 0.0005 0.0011
			Full cubeful rollout with var.redn.
			1297 games, Mersenne Twister dice gen. with seed 722859899 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	3	R	5/off 3/off	+0.3201 ( -0.0177)
			0.6936 0.0429 0.0002 - 0.3064 0.0000 0.0000 +0.4304 +0.3201 0.0005 0.0008 0.0000 - 0.0005 0.0000 0.0000 0.0007 0.0011
			Full cubeful rollout with var.redn.
			1296 games, Mersenne Twister dice gen. with seed 722859899 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]

---

DMP rollout:

Double Match Point. Blue to play 5-3.

White	87
Blue	39
Position ID: ttsNABDPvQEAAA Match ID: cIkuAAAAAAAE

Alert: unlucky roll! ( -0.423)

#		Ply	Move	Equity
•	1	R	5/2* 5/off	+0.3844
			0.6922 0.2097 0.0005 - 0.3078 0.0000 0.0000 +0.3844 +0.3844 0.0005 0.0097 0.0002 - 0.0005 0.0000 0.0000 0.0010 0.0010
			Full cubeful rollout with var.redn.
			1296 games, Mersenne Twister dice gen. with seed 722859899 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	2	R	5/off 4/1	+0.3713 ( -0.0131)
			0.6857 0.2693 0.0075 - 0.3143 0.0000 0.0000 +0.3713 +0.3713 0.0005 0.0098 0.0011 - 0.0005 0.0000 0.0000 0.0010 0.0010
			Full cubeful rollout with var.redn.
			1296 games, Mersenne Twister dice gen. with seed 722859899 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]
	3	R	5/off 3/off	+0.3677 ( -0.0167)
			0.6839 0.2819 0.0133 - 0.3161 0.0000 0.0000 +0.3677 +0.3677 0.0006 0.0097 0.0014 - 0.0006 0.0000 0.0000 0.0012 0.0012
			Full cubeful rollout with var.redn.
			1296 games, Mersenne Twister dice gen. with seed 722859899 and quasi-random dice
			Play: supremo 2-ply cubeful prune [world class]
			keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
			Skip pruning for 1-ply moves.
			Cube: 2-ply cubeful prune [world class]

Messages In This Thread

• Bearoff position, cubeful
  Daniel Murphy -- Saturday, 14 September 2013, at 8:20 a.m.
  • Bearoff position, cubeful
    ah_clem -- Saturday, 14 September 2013, at 2:32 p.m.
    • Bearoff position, cubeful
      Bob Koca -- Saturday, 14 September 2013, at 2:55 p.m.
      • Bearoff position, cubeful
        ah_clem -- Sunday, 15 September 2013, at 12:12 p.m.
  • Bearoff position, cubeful ROLLOUT
    ah_clem -- Wednesday, 18 September 2013, at 8:54 p.m.
    • Bearoff position, cubeful ROLLOUT - Gnubg
      Daniel Murphy -- Thursday, 19 September 2013, at 4:16 a.m.